EP 0 886 725 B1 discloses a method for determining an estimated value of a mass flow in the cylinders of an internal combustion engine. In this case, the estimated value of the mass flow in the cylinders of the internal combustion engine is determined depending on a measured value of a mass flow upstream of a throttle valve in the intake channel, on the degree of opening of the throttle valve, on the rotational speed, on the crankshaft, on a measured value of the induction manifold pressure, and on further operating variables of the internal combustion engine. A dynamic model of the intake channel of the internal combustion engine is provided for this purpose. The dynamic model is corrected during operation, depending on the measured value of the mass flow in the intake channel and on a difference between a measured value and an estimated value of the induction manifold pressure, which difference is supplied to a controller, whose manipulated variable is used for correcting the dynamic model of the intake channel.
Under specific load conditions of the internal combustion engine—in particular in the case of an internal combustion engine with four cylinders—significant pulsations of the gas mass in the intake channel occur, and these pulsations can cause a significant corruption of the measurement signal of the mass flow meter. It is therefore known from EP 0 886 725 B1 that the measured value of the mass flow meter should not be used for correcting the dynamic model of the intake channel under these conditions. However, this can lead to a loss of precision when determining estimated values using the dynamic model of the intake channel.